It is common practice in many industries to design equipment including modular hardware components. This allows hardware components to be replaced or exchanged with ease without requiring overall equipment modification. In many areas, equipment suppliers have found copying of their hardware components to be a problem. It has been found that unauthentic components sometimes do not meet the equipment suppliers' quality standards and/or do not interface properly with the equipment. Customers experiencing difficulty with unauthentic components often attribute the negative experiences to the equipment suppliers. This has led equipment manufacturers to incorporate authentication mechanisms into their equipment to inhibit unauthorized copies of hardware components from being used in their equipment.
For example, U.S. Pat. No. 4,723,284 to Monk et al discloses a hardware authentication system for a public key communications network. The public key network includes at least one user terminal and at least one hardware authentication terminal coupled to the user terminal. The authentication terminal generates and stores a plain text message therein. The authentication terminal also generates from the plain text message, a cipher text message by transforming the plain text message with the public key of the user terminal and transmits the cipher text message to the user terminal. The user terminal is adapted to receive the cipher text message and transform the cipher text message with its private key to obtain a plain text message. The user terminal also transmits the plain text message back to the authentication terminal. The authentication terminal compares the plain text message received from the user terminal with the plain text message stored therein to determine coincidence. If the two plain text messages match, the authentication terminal generates an authentic user signal indicating that the user terminal is the hardware terminal associated with the public key.
U.S. Pat. No. 4,799,635 to Nakagawa discloses a system for determining the authenticity of computer software stored in a ROM cartridge when used with a main processor unit. To verify that the ROM cartridge is authentic, duplicate semiconductor devices are included in the ROM cartridge and the main processor unit. The semiconductor device associated with the ROM cartridge acts as a key device and the semiconductor device in the main processing unit acts as a lock device. The key and lock devices are synchronized and execute the same arithmetic operation according to pre-programming. The results of the executed arithmetic operations are exchanged between the semiconductor devices and compared. If the results agree, the ROM cartridge is determined to be authentic and the main processing unit is allowed to operate. If the ROM cartridge is determined to be unauthentic, the main processing unit is continuously reset inhibiting it from operating.
U.S. Pat. No. 4,766,516 to Ozdemir et al discloses a security system and method for protecting an integrated circuit from unauthorized copying. During design the integrated circuit is provided with at least one additional circuit element that does not contribute towards the function of the integrated circuit. Rather, the additional circuit element is designed to inhibit operation of the integrated circuit when an unauthorized copy of the integrated circuit is made. The additional circuit element has the visible appearance of being functionally interconnected to the integrated circuit but actually is not. Thus, in an authentic device, the additional circuit element is isolated from the integrated circuit. However, when a copy is made, if the copier copies the integrated circuit according to its visual appearance, the additional circuit element will be physically connected to the integrated circuit and the operation of the additional circuit element will inhibit proper operation of the integrated circuit.
Although the above-identified references disclose systems and methods to deter copying, new authentication systems and methods are of course desired. It is therefore an object of the present invention to provide a novel hardware authentication system and method.